type MyReadonly2<T, K extends keyof T = keyof T> = {
    [P in keyof T as P extends K? never: P]: T[P]
} & {
    readonly [P in K]: T[P]
}

interface Todo {
    title: string
    description: string
    completed: boolean
}

type Keys = keyof Todo
// Keys = "title" | "description" | "completed"
